Millions of tons of tomatoes are processed annually into a variety of tomato products, such as canned whole tomatoes, catsup, tomato paste, tomato puree, tomato sauce, and the like. During the short harvest season, which typically is about forty to sixty days long, the tomato industry processes raw tomatoes to both final products and partially processed products for storage and remanufacture. After harvesting, tomatoes must be quickly processed into the desired end product in order to avoid spoilage. In common practice, tomatoes are harvested at the pre-ripened stage so that the tomatoes retain a firm texture during handling and transport, in order to minimize spoilage. However, pre-ripened tomatoes lack the sweet and fruity characteristics of vine-ripened tomatoes.
It is recognized in the tomato processing industry that consistency is an important attribute of many products, including tomato juice and products prepared therefrom, such as paste, sauce, puree, catsup, etc. "Consistency" refers to the apparent viscosity of the product and the tendency of the product to hold its liquid portion without separation. To measure consistency, commercial tomato processors employ the Bostwick consistometer, which measures a flow property of a viscous tomato product. The operational aspects of the Bostwick consistometer are well known. Higher consistency in processed tomato products is perceived to represent better quality. In the processing of such tomato-based products it is recognized that product consistency is dependent upon the presence of pectic substances in the tomatoes, and may be controlled to some extent by the method of manufacture of the tomato based products. That is, two general commercial processes are employed in the manufacture of tomato products. In the "hot break" method, tomatoes are macerated at a temperature of 185.degree. F. (85.degree. C.) or higher to inactivate enzymes in the tomato, particularly pectin enzymes, such as pectin esterase and polygalacturonase. These pectic Enzymes are primarily responsible for the breakdown of pectic substances in the tomato, which results in undesirable low consistency of tomato products. In the "cold break" method, the tomatoes are macerated at some temperature below 185.degree. F. (85.degree. C.), at which pectin degrading enzymes remain active. In commercial practice the hot break process is used in the manufacture of tomato paste, puree, sauce, etc. where a thick consistency is desirable, while the cold break process is used for tomato products in which thick consistency is not a sales advantage.
Thus, conventional hot break processing of tomatoes successfully inactivates all tomato enzymes, including the pectin degrading enzymes, and thereby preserves consistency in the resulting product. However, since the hot break treatment effectively inactivates all tomato enzymes, including those responsible for the development of the desired sweet and fruity taste characteristic, of vine-ripened tomatoes, tomato products produced by the typical hot break process are commonly deficient in such desired flavor characteristics.